"I couldn't really get past anybody that would spend the money that it would take to do it and keep an R rating," Verbinski said. "Alternately, I wasn't really interested in pursuing a PG-13 version. Because the R rating is inherent. Little Sisters and injections and the whole thing," said Verbinski.

The next game in the series, BioShock Infinite, moves away from the underwater setting of Rapture and into the floating city of Columbia.

BioShock Infinite will be released on Xbox 360, PlayStation 3 and PC on October 16 in North America and October 19 in Europe.